focus on things further away

[christiand]

Hi all,

I have the feeling that focussing on things further away, starting at about some hundred meters away even with the 70-200 VR is giving me grief.
Things close, such as portraits are exeptionally sharp.
Who has an answer to what I am experiencing ?
Who is experiencing the same and hasn't got a clue why ?

Your answers are very much appreciated.\

Cheers
CTD

[christiand]

hi dudes and dudettes,

I'm shamelessly bumping !
I'd like to to capture some response to my 70-200 VR dilemma.

Cheers
CD

[sirhc55]

You have bumped in my direction CD but I feel there is no easy answer here. Is it only the 70-200VR this happens on or all lenses? Are you using the centre focus spot and have it in AF-S?

Please give some settings so that we have a starting point.

[Onyx]

Tried focusing at hyperfocal distance? Result favourable or not? Perhaps the holy grail of lenses (at least I consider it to be) has a weakness after all!

[Killakoala]

Try a smaller aperture, say about F7-10, see if that helps.

Also you could try manual focussing. The focal PLANE that the lens is attempting to focus in is much longer and at a lower angle than would be with a solid object close-up.

For example. Imagine focussing on a brick wall, 10 metres in front of you. It would be easy to focus correctly on this. If however, the wall is at a 45deg angle, then it becomes harder to focus on it. If it is laying flat, then focussing is of course, very hard. In this case, the best thing you could do is increase your depth of field by adjusting apeture.

My two cents.

[Glen]

Hi Christian, I have the same problem with a s/h 400mm 5.6 I have, it doesn't focus well at infinity. I haven't bothered to fix it yet. Some have said these problems can be due to atmospheric haze, vibration, etc. I don't believe that is my case.

As a comparison, here are two shots from my 70-200 + 1.7 TC. The top of the bridge is 2.5kms from me, one shot is the shot, the crop is 100% crop of the flags so they are 2.5kms away. Is your lens as good, better or worse than this shot at distance? This was shot from my Gitzo to test it out, with remote so pretty stable, exif is attached. 340mm F8 1/1250 at ISO 400 (forgot to switch back).

Shot






100% crop






Hope this helps Christian

[gstark]

Christian,

I observed a similar problem when trying to manually pre-focus the 80-400 in Melbourne at the F1GP; the camera worked well in AF mode, but not so well in MF. I was both surprised and disappointed.

The D70's viewfinder doesn't help matters much here either; it is somewhat smallish, and the screendoesn't have the focussing aids that some the older cameras, such as my FE2, have.

The ability to swap in an accessory screen, with a diagonal split prism, would be a nice improvement.

Glen, was your shot made through window glass? There seems to be a reasonable amount of heat haze in the full crop, and the shadow on the rh side, plus the darkish spots (or are they dust bunnies) to the right of the top of Sydney Tower lead me to ask this question.

[Glen]

Spot on about the heat haze Gary, I seem to get that often when taking bridge shots from here. It was a reasonably hot day, but it seems heat haze or atmospheric disturbances do affect my setup at this distance. The crap in the full crop is my garden, someone has been too busy playing with his camera to attend to the garden. Terri suggested we get a gardener on the weekend, seems she is not the only one noticing The shot was never intended to be an image, more of a test of the Gitzo 1348 + RRS 55 ballhead over 2.5kms, so didn't prune the garden

[sirhc55]

Glen - that heat haze is not caused by nature, it is your hot breath salivating over the Gitzo

[Glen]

You could be right Chris

Here is a shot from next to Blues Point, well known to D70 users and about a kilometre from the bridge. This is a 100% crop and seems to have less heat haze (or Gitzo salivation).

[birddog114]

Glen,
Need new Gitzo tripod and the Wimberley sidekick

[Glen]

Glen,
Need new Gitzo tripod and the Wimberley sidekick

You forgot 200-400 Vr and D2X to go on top

[gstark]

Glen,

That's one hell of a distance over which to be taking photos, and even on a coolish day, haze and or pollution may be stepping up to the mark and introducing some unwanted elements into the equation.

As to the garden ... now you know one reason I live in an apartment. That's a nice thing about living in apartments in the US - you get the gardening all done, plus, usually a pool or two on the premises as well.

But I digress.

The newer image is a far better example for Christian to be looking at, if only because of the lesser distance and therefore less chance for the introduced elements to be affecting the results.

[gstark]

Glen,
Need new Gitzo tripod and the Wimberley sidekick

You forgot 200-400 Vr and D2X to go on top

Leigh's decided that he wants to borrow that combination for the next full moon ...

[birddog114]

Glen,
Need new Gitzo tripod and the Wimberley sidekick

You forgot 200-400 Vr and D2X to go on top

Leigh's decided that he wants to borrow that combination for the next full moon ...

Why not? tell him come over and pick them up.

[yeocsa]

Hi

IMO, several factors contributed to the problem:-

Severity in the following order, with the worst at the top:-

1. Use of TC degrades image quality. It becomes less of a 70-210 VR.
2. Atomospheric factors - heat, pollution, haze. why? picture is not taken early or late in the day.
3. Camera vibration as there's no mirror lock up.
4. Vibration coming from the connections between the lens, TC and camera body.
5. Camera AF. D70's AF is not as precise as the more expensive D1 and D2 series.


regards,

Arthur

[Glen]

Gary, you are spot on about gardening Also you are right about the distance, just trying to highlight a long shot for Christian.

Without boring everyone with every longer shot I have taken, here are a couple more representative samples taken whilst trying to shoot yachts at Bradleys Head.

Here is what looks like a Dragon and a skiff going to cross masts (they didn't)






here is a seaplane crop at 100%






Sorry, don't know the distances. All these taken handheld. See how your lens compares, Christian. I don't think any of these are super sharp, but are representative of my lens at the 1km to 2.5km mark. Hope this helps, Glen


Leigh could take the footprints on the moon with that combo

[christiand]

Thank you all so much for your responses.

I have prepared a few photos for comparison.
Shops at a distance of about 1km, f-8, 1/800 and 1/640

70-200VR at 100%:



70-200 VR at 200%:



70-200VR + TC17 at 100%:



70-200VR + TC17 at 200%:



I think that I'm actually getting very similar results compared to your examples.

Please let me know what you think.

Cheers
CD

[gstark]

Christian,

They look good to me.

Why not try something like a car at about 500 meters, perhaps at a set of traffic lights; what detail can you see in the various features, such as head or taillamps, license plate, and so on.

I've found that sort of thing to be an excellent start for a subjective test such as this.

[Glen]

I agree with Gary, think they look ok. Arthur's suggestions probably apply to both. I will get a shot at 500metres as a comparison.

[birddog114]

CD,
It's MacDonald perhaps it will be better with Hungry Jack or Burger King

[Nnnnsic]

Leigh could take the footprints on the moon with that combo

Why else do you think I want it?

Who needs NASA?